Generally, vehicles are classified according to their body styles such as passenger vehicles, commercial vehicles (bus, trucks, etc.) and the like. Vehicles are also categorized according to the type of fuel used in the automobiles, e.g., gasoline engine vehicles, diesel engine vehicles, or Liquefied Petroleum Gas (LPG) engine vehicles.
In order to generate engine power in diesel engine vehicles, fuel is injected under high pressure (around 100–300 atmospheric pressures) into the combustion chamber filled with compressed air under about 40 atmospheric pressures at 500–550° C. That is, the injected fuel is self-ignited by the compressed heat of air and converts thermal energy into mechanical energy for use as diesel fuel.
Since the fuel injection pressure of the diesel engine is very high, it can be important to maintain a sufficient fuel pressure until the fuel pumped from the fuel tank is injected into the injector. Thus, a proper fuel supply pressure should be maintained at all times to readily deliver fuel to the combustion chamber even when the vehicles accelerates rapidly.
A fuel supply system for diesel engine vehicles is typically designed to pump fuel from a fuel tank, heat the fuel at a desired temperature and then inject it through an injector after passing through a filter. However, this causes an inevitable fuel pressure loss at about 360 mbar while the fuel passes through each of the above components despite an initial high fuel supply pressure.
Additionally, when the fuel pressure loss is about 360 mbar in such a diesel engine fuel supply system, the amount of loss typically increases over time.
Such excessive fuel pressure loss can pose notable problems. Thus, when the fuel pressure loss is about 360 mbar or more in the fuel supply system, a proper fuel supply may not be provided during rapid acceleration, thus deteriorating the engine operation of a vehicle. Additionally, if the fuel pressure loss is about 360 mbar or more, then a controller may make an erroneous determination for an inlet metering valve that regulates the fuel pressure.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.